Food is any material consumed to supply nutrition to the organisms. It is generally of animal, plant or fungal source, and comprises necessary nutrients, including vitamins, proteins, carbohydrates, or minerals. The nutritional value of food is determined by its physiological properties, and the proportions of nutrients required by the body are considered to be nutritionally acceptable or nutritionally adequate. An animal feeds on grass, while a plant grows best in the shade, on the availability of water.
Nutrient combination in food to ensure that the nutrients are assimilated efficiently and that the food provides energy. Each nutrient is required for different physiologic functions and some other nutrients serve only to increase the basic functions of life. Nutritious diets are important for obtaining all the necessary nutrients in the form of macronutrients which are substances that cannot be found in plant food sources. Examples of macronutrients are fatty acids, phosphorous, calcium, magnesium, potassium, nitrogen, iodine, phosphorus, silicon, selenium, zinc, iron, vitamins A, B, C and D and essential fatty acids.
Food with a lot of water and relatively few fibrous carbohydrates are recommended as fat free diet. The fat free diet is effective in reducing weight and improving the general health of an individual. Food containing large amounts of sugar should be restricted, because sugar contributes to the growth of pathogenic bacteria and fungi. Large amounts of dietary fibre are necessary to improve the general health of the human body, but excessive intake of fibre may lead to constipation. Foods that contain soluble fibre are easily digested and used as energy by the body.
The immune system is the first line of defence against many diseases and infections. Vitamin B12, folic acid, riboflavin, vitamin C, thiamine and niacin are contained in certain foods, which are required for the healthy functioning of the immune system. These vitamins are also important for maintaining healthy skin and hair. In order to get sufficient quantities of these vitamins one needs to eat a healthy diet, which is rich in dietary fiber.
Palm oil is extracted from fruits of red palm oil trees and can be consumed regularly as food source. Palm oil is the best source of monounsaturated fatty acids, which are very good for the health and welfare of the heart and cardiovascular system. Foods that are rich in polyunsaturated fatty acids (Vitamin E) include sunflower seeds, nuts, olive oil, olives and tropical fruit juices. Sunflower seeds contain a type of omega 3 fats that is very beneficial for the heart and should be consumed in the form of supplements.
Fruits and vegetables contain a class of compounds known as polyphenols. These compounds play a role in the formation of energy, essential fatty acids, the synthesis of DNA and the release of energy from food. The total energy produced in the body from foods rich in polyphenols is known as e.g. EGCG, which is abbreviated as EGC.